Oscillator system



Dec. 21, 1948. WALSH v 2,456,802

OSCILLATOR SYSTEM Filed July 22, 1946 INVENTOR.

Patented Dec. 21, l948 :76.-

UNITED STATES PATENT OFFICE Philip J. Walsh, San Francisco, Calif.

Application July 22, 1946, Serial No. 685,335

This invention relates to a system for converting direct current into alternating current.

In my U. S. Patent 2,445,897, for Alternating current system, filed April 29, 1946, I describe a method for the conversion of direct current energy into alternating current energy in a system requiring no electronic emission devices or moving parts.

It is an object of this invention to improve the system described in my prior application.

It is another object of this invention to provide a efiicient high frequency oscillation generator and power multiplier.

My invention possesses many other advantages and has other objects which may be made more easily apparent from a consideration of one embodiment of my invention. For this purpose, I have shown a form in the drawing accompanying and formin part of the present specification. I shall now proceed to describe this form in detail, which illustrates the general principles of my invention; but it is to be understood that this detailed description is not to be taken in a limiting sense, since the scope of my invention is best defined by the appended claims.

Referring to the drawing, the single figure Is a system diagram depicting one form of my invention.

In the drawing I show a source of alternating current potential I connected through the two position switch 2 to the terminals 3 and 4, across which is connected the parallel resonant circuit comprising thewindings 5, 6, I and the variable condenser 8. The windings 5 and 8 wound on the tubes 9 and ID of insulating material are coupled to the windings I I and I2 respectively to form two separate transformers. The windings II and I2 being connected together through the parallel resonant circuit I'3 which acts substantially as a pure resistance at its resonant frequency.

The batteries I5 and I6 are connected in series across the coils 5 and Ii and would, in the absence of other factors, send direct current through these coils, and since the coils are equal and the batteries apply equal electromotive forces to the system, there would be no direct current difierence of potential across the terminals 3 and 4. The switch I4 is arranged so that when it is closed, both direct and alternating currents are applied to the system simultaneously in order to prevent a large flow of direct current through the coils.

In the operation of the system the switch 2 is closed first in the full line position, after which the switch I4 is closed. When the alternating current potential from the source I makes the terminal 3 positive and the terminal 4 negative, current flows in the direction of the full line arrows through the coils I, 5 and 6 and the batteries I6 and I5. The value of the current flowing 5 Claims. (Cl. 250-36) from terminal. 3 through the coil 6 and battery I5 to terminal 4 is very much greater than the value of the current flowing from terminal 3 through the coil 5 and battery IE to terminal 4, because the electromotive force of battery I5 is in series assisting relation with the electromotive force of the source I while the electromotive force of battery I6 is in series opposed relation with the electromotive force of source I. The value of the reverse current flowing through the battery I6 is a function of the applied alternating current potential of source I and of the impedance of circuit I3.

The current flowing in the coils H and I2 at this instant, flows in the direction of the arrows with the coil I2 acting as a source of current and the coil II acting as the primary of a series transformer which induces an electromotive force in the coil 5 of such a direction as to assist the electromotive force of the source I and causes a small reverse current to flow in the direction of the arrows through the battery I6. The coil II acts as a load across the coil I2 thus causing more current from battery I5 to flow through coil 6 and reverse current to flow through battery l6. Adjustment of the tap l'l determines the amount of current flow through the coil II--the circuit l3 acting like a series resistor.

If the peak or maximum electromotive force of the source I is made equal to that of one of the batteries, such as, I6, and the tap I"! is set to its highest impedance point (maximum resistance) there would be no reverse current flow through the battery I6 and this part of the system would operate as described in my prior patent referred to on page 1. v

With some reverse current flowing through the battery 16 the condenser 8 cooperates with the coils 5, 6 and I to form a parallel resonant circuit across the terminals 3 and 4. It is to be noted that this parallel resonant circuit has a pendulum or flywheel effect, and that the value of the current surging between the condenser 8 and the coils 5, 6 and I is very much greater than the value of the current fiowing into it from the terminals 3 and 4.

During the other half of the cycle of applied alternating current from the source I the actions are reversed and the currents flow in a direction opposite to that indicated by the arrows. That is, terminal 4 is positive and terminal 3 negative so that the electromotive force of source I is in series assisting relation with the electromotive force of battery I6 and in series opposed relation with the electromotive force of battery [5. The

large current now flows from terminal 4 through battery It and coils 5 and I to terminal 3. The coil II now acts as a source of induced current and sends current through the circuit I3 and coil I2 in a direction opposite to that indicated by the arrows. The electromotive force induced in the coil 6 by this current flowing through the coil I2 assists the electromotive force of the source I to send a small reverse current through thebattery I in a direction opposite to that indicated by the arrows. That is, the coil I2 is now acting as the primary of a series transformer and the electro motive force induced in the coil 6 is a function of the valve of the current flowing in the 0011 I2. Now the coil I2 acts as a load across the coil II thus causing more current from the battery I6to flow through coil 5 and reverse current to flow through battery I5.

A load such as I8, which could be an antenna, or an arrangement for high frequency heating, etc, is connected across theterminals Hand The energy dissipated in the load I8 is supplied by the combined action of the batteries and the source I and is greater than the alternating currcnt energy fed in at the terminals 3 and 4 bythe source I.

When the switch 2 is thrown over'tothe dotted line position, the source I is dlsconnect'ed'andthe coil 2i is connected to the terminals 3 and M This switch is arranged for fast snap action and has a wide arm so as to span both contacts and thus connect the coil 2| before disconnecting'the source I. The alternatin current potential in-- duced in the coil 21 by the parallel resonant tank circuit I3' is now applied tothe terminals 3- and 4 and operates to trigger off energy from the batteries I5 and I6 so=that the system continuesto produce alternating current energy in the load I8 with the source I: disconnected.

This system differs fromthat shown in my prior patent referred to on' page 1, initha't the circuit including the coils II and l fisemployedt'osupply feedback energy to maintain' the system in a state of continuous oscillation, the load currents being taken from another transformer including the coil 1, thus making it possible to operatemore efficiently,

The unit 23' is a power multiplier stage in." which' the output from the. terminals I9 and 20 can be combined with energy from the-batteries I5" and. I6 to produce a larger power output in' a load such as I8. Since the operation'ofthis' stage is similar to that of the first stage the numerals: designating corresponding parts have been primed.

In the operation of this stage, theswitch 22 is closed first, after which the switch I4 is closed. It is seenthat when the terminal3' isspositive ands the terminal 4 negative, current flows from terminal 3 through the coil-1' to'thepoint 25 where the current divides, most of it flows through coil; 6' and battery I5;. the small part flowsthrough coil 5 and as reverse. current throughbattery I6 to. terminal 4 Since the voltage of battery I5 is in"v series" assisting relation with the voltage fromtterminals; I9 and 20, direct current energy from the. battery I5 combines in coil 1- withalternating current: energy from terminals I9 and 20 to: produce more alternating current energy inv the. load I8 than is fed in from theterminals I9and2flt During the other half of the cyclewhen' the terminal 4' is positive and the terminal 3 negative, most-0f the current flows from terminal 4 through the. battery I6,,coil 5', coil I to-terminali. Since the voltage of battery I6 is-now in series asaiste in; relation with the voltage from terminals I9 4 and 20, direct current energy from the battery It combines in coil I with alternating current energy from terminals I 9 and 20 to produce a greater amount of alternating, current energy in theload l8 than is fed in from theterminals I9 and 20. The currents flowing in the coils II and I2 serve to induce voltages in the coils 5 and 6' at the proper times to produce a small reverse current through one of the batteries as was described in connection with the first stage.

coul'dbe operated as'anoscillator and the-second stageas a power'multiplier try-form" aradio trans mitter. employed; the systemoperatesat' high efficiency directly from a* very low: voltage source of direct current;

I' claim:

1. In combination, a tuned circuit having two branches and-a common branch; a source of direct current in each of saidtwo branches, and means including a souroe'oi alternating current potential:coupled tosaidcomm'ombranch to' alternately' opposetiie'flow of current fronrone of saiddirect current sources while increasing" the flow of current through thexotherdirect current source during each cyclel and arrcutputcii'cuit coupled to said common branch.

2: Thelsystem" as claimed in claim 1; with the additiomof 'means coupling said twobranches to increase the flow of-cur-rentthrough one of-said directucurrentsources and reverse the direction on current'flowwthrougliu the other direct current source during each cycle.

3'. The system: as claimed in: claim 1 with the addition: or means coupled' to said two branches to feed back: energy to said common branch to sustain continuous oscillations upon removal of said: original tential:

4 1. In: a: system oi the: character described, a

source ot alternating current pomulti stago power multiplier" comprising a plu-- may of simllarrsta'ges, each-including a circuit having. two branches andi a common" branch, a

source: of direct current in eachof said two branches, andlrne'ansi including a source of alternating curnentpotential coupled tosa'id common branch to'aiternately opposeltheflow of current from: one of said directi current-sources while increasing: the flow of current through the other direct" currenti source": during. each cycle, an output circuit coupled to said comm'onbranch, and

means for feeding: theoutput: power of one stage into the input? of the next. stage;

5; 'I'h'esystem'" acclaimed in cla im 4, with the addition: ofJfeed -bach means in the first stage to sustain: continuousoscilla'tionstherein upon removal of the original source of alternating current potential coupled tolthelinput of this stage.

PHILIP J, WALSH.

No: references cited;

Since no electronic emission devices are 

